From 09f4d0d9b76cdbedbe91bc07ca0409b74f2172ee Mon Sep 17 00:00:00 2001 From: balrog Date: Sun, 7 Dec 2008 03:07:51 +0000 Subject: [PATCH] LSI53C895A: Handle empty SCRIPTS opcode (Justin Chevrier) Basically after each DMA transfer the Openserver driver would issue an empty (0) SCRIPTS opcode. As the opcode is essentially a NOP it has no second DWORD and therefore the DSP should only be incremented by 4 bytes instead of the 8 bytes we currently do. Here's a snippet of the log: lsi_scsi: Data ready tag=0x100d9 len=16384 ... lsi_scsi: SCRIPTS dsp=068c5e50 opcode 01000400 arg 07a09000 lsi_scsi: DMA addr=0x07a09000 len=1024 lsi_scsi: SCRIPTS dsp=068c5e58 opcode 00000000 arg 01000400 lsi_scsi: Wrong phase got 1 expected 0 Note the 2nd DWORD after the empty opcode; the next opcode in the DMA transfer sequence. As can be expected the address after that has the next DMA address to use. After the attached patch the DMA transfer is able to complete successfully: lsi_scsi: SCRIPTS dsp=068c5e50 opcode 01000400 arg 07a0d000 lsi_scsi: DMA addr=0x07a0d000 len=1024 lsi_scsi: SCRIPTS dsp=068c5e5c opcode 01000400 arg 07a0d400 lsi_scsi: DMA addr=0x07a0d400 len=1024 ... Tested againsted Openserver 5.0.5 and Debian ARM. Signed-off-by: Justin Chevrier Acked-by: Ryan Harper Signed-off-by: Andrzej Zaborowski git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5902 c046a42c-6fe2-441c-8c8c-71466251a162 --- hw/lsi53c895a.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/hw/lsi53c895a.c b/hw/lsi53c895a.c index aa6c600..8748766 100644 --- a/hw/lsi53c895a.c +++ b/hw/lsi53c895a.c @@ -867,6 +867,12 @@ static void lsi_execute_script(LSIState *s) again: insn_processed++; insn = read_dword(s, s->dsp); + if (!insn) { + /* If we receive an empty opcode increment the DSP by 4 bytes + instead of 8 and execute the next opcode at that location */ + s->dsp += 4; + goto again; + } addr = read_dword(s, s->dsp + 4); addr_high = 0; DPRINTF("SCRIPTS dsp=%08x opcode %08x arg %08x\n", s->dsp, insn, addr); -- 2.7.4